Elevator plural car system including means to select one group of cars as the active group



I Filed Dec. 10, 1963 April 9, 1968 |$AQ |NUZUKA ET AL 3,376,953

ELEVATOR PLURAL CAR SYSTEM INCLUDING MEANS TO SELECT ONE GROUP OF CARS AS THE ACTIVE GROUP 2 Sheets-Sheet 1 INVEl/7'08S' ATTORNEY April 9,1968- ISAO INUZUKA E L Filed D60. 10, 1963 ONE GROUP OF CARS AS Fig. 2

THE ACTIVE GROUP 2 Sheets-Sheet 2 420 K 3 0113 EDT/21;;

lice /C02 {/92 ATTORNEY United States Patent 3,376,953 ELEVATOR PLURAL CAR SYSTEM INCLUDING MEANS T0 SELECT ONE GROUP OF CARS AS THE ACTIVE GROUP Isao Inuzuka and Kikuo Watanabe, Katsuta-shi, Japan, assignors to Hitachi, Ltd., Tokyo, Japan, a corporation of Japan Filed Dec. 10, 1963, Ser. No. 329,559 Claims priority, application Japan, Dec. 12, 1962, 37/54,983 5 Claims. (Cl. 187-29) ABSTRACT OF THE DISCLOSURE This invention provides an elevator controlsystem for a plurality of elevators. The control system divides the elevators into a plurality of different groups with each group having a plurality of elevators. Each group includes first-starting car selection means which operate independently of the first-starting car selection means of other groups for selecting one of the elevators in the group as the first starting car at the main floor. Service demand detecting means are provided for detecting whether the service demand for the elevators is normal or slack. Control means are provided which are operated by the service demand detecting means and include means for isolating each group so that it can be operated independently of the other group when the service demand is normal and means for interconnecting all of the groups when the service demand is slack. In addition, priority selection means are provided which are controlled by the control means for giving a priority in dispatch to one of the groups while the service demand is slack. The priority selection means include interlocking'means for maintaining groups other than the group given priority non-operative during the slack service condition and shifting means for making one of the other groups to select one of its available cars as a first-starting car, irrespective of the priority, if there is no available car at the main floor in the group which has been given priority by the priority selection means.

With the recent advent of large-scale buildings, there is a trend of increase in the number of elevators installed in a single building. The present invention is intended to provide an improved control system for operating a large number of elevators installed in a building in groups each including usually four to six elevators. Elevator groups are generally arranged in side walls of a large room opposite to each other, thus leaving a space therebetween as a waiting floor. In other cases they are arranged by the walls of cross corridors in an L formation or arranged at separate places.

Such group arrangement necessitates a signal controlling device for each elevator group. With such known arrangements, eificient operation has been obtained during the time when it handles a relatively large trafiic. However, the operation efiiciency is reduced while it handles a small traflic. The reason is'that since the elevator groups are controlled independently from each other, all of the groups should respond to sporadic landing calls so that some cars make idle runs.

The present invention has for its object to provide an elevator control system of the kind described which is highly efiicient in operation during the peaks of trafiic and enables economic operation of the entire elevator plant even while the traflic is small.

Another object of the present invention is to provide an elevator control system of the character described including a simplified control circuitry adapted to both 3,376,953 Patented Apr. 9, 1968 separate control of the elevator operation thereof.

A further object of the invention is to provide an .elevator control system in which cars are dispatched at the main floor alternately from the elevator groups .for the purpose of increasing the handling capacity of the entire elevator installation during the peaks of tratlic to give satisfactory service to the passengers.

These and other objects and advantages of the present invcnton will become apparent from the following description when taken in conjunctionwith the accompanying drawings, which illustrate one preferred embodiment of the invention and in which:

FIG. 1 diagrammatically illustrates a first-starting car selecting circuit according to the invention; and

FIG. 2 diagrammatically illustrates a first-starting car group selecting circuit which coacts with the circuits of FIGURE 1.

In the drawings, there is illustrated a control system embodying the present invention usable with two elevator groups each including three elevators. The three elevators in the first group are designated herein by. A, B and C, and those in the second group by D, E and F. The control system includes means for detecting if the service demand is normal or not. One of such means will perform its function by summing up the total number of calls registered in the entire elevator plant and thus by determining whether the total exceeds a specified number or not. Another will perform its function by summing up the number of can travels and determining whether it exceeds a specified number of travels or not. This means includes a contact 1 which is closed when the service demand is normal and opens when it becomes small or slack. Reference numeral 2 indicates an operational route contactor common to both the elevator groups. Reference characters A, B, C, D, E and F indicate first-start contactor for the respective cars. Upon energization of any'of these first-start contactors the elevator corresponding to the contactor is designated as a first-starting elevator at the main floor and thus the elevator is made ready for groups and coordinative start, for example, opening the door and inviting the waiting passengers to enter the car.

Reference characters 3A, 3B, 3C, 3D, 3E and 3F are 7 D, E and F. These contacts are arranged so that, when the trafiic is normal or the contact 1 is closed, (1) contact 3B is closed it the firststart contactor A is held on, (2) contact 3C is closed if the first-start contactor B is held on, and (3) contact 3A is at any other floor, contact 3C instead of contact 3B is thrown in. If two cars B and C are both at any other floor or floors, neither of the first-start preparing contactors 3B, 3C is closed. With the first-start contact 3A is closed if the contactor C is held on. However, in the case (1), if the car B is at any othe floor, contact 3C instead of contact 38 is thrown in. If two cars B and C are both at any other fioor or floors, neither of the first-start preparing contractors 3B, 3C is closed. With the first-start contact 3A is closed instead of contacts 3C if car C is at any other floor. Likewise, in the case (3), contact 3B will be closed if the car A is at any other floor. Hence, it will be seen that this operation decides the next starting car for each group, depending 'uopn the actual position of each car. Similar contact operation also takes places in the second group including cars D, E, and F.

Next, when the traffic is slack and the contact 1 is open, (1) contact 3B is closed if contactor A is closed. If car B is at any other floor, not contact 3B but contact 3C is closed. This operation is the same as in the case (1). However, if both cars B and C are at any other floor or floors, neither contact B and C is closed but the contact 3D of the first-start preparing contactor for car D in the second group is closed. If car D is also at any other floor, contact SE is closed, and, if car E is also again at any other floor, contact 3F is closed. Next, (2) in case contactor Bis in a closed state, contact 3C is closed. If car C is at any other floor, contact 3A is closed. However, if both cars C and A are at any other floor or floors or there is no car at the main fio-or in the first group to start first, contact SD of the first-start preparing contactor for car D in the second group is closed to select car D as the first-start car. Also in this. case, if car D is at any other floor, not contact 3D but contact 3E is'closed. If car E is also at any other floor, SE is not closed but 3F is closed to select the next first-starting car. (3) The same process occurs also in the case where the contactor C is thrown in. This also applies to cases where first-start contactor D, E or F of the second elevator group is thrown in.

Referring to FIG. 2, reference numeral 41 designates a first-start holding contactor for the first group including cars A, B and C; and 42 designates a first-start holding contactor for the second group including cars D, E and F. Reference character T indicates a time limit relay designed to operate after a predetermined time upon deenergization thereof. Contactors 61 and 62 designate group interlocking contactors for the first and second car groups, respectively. Referring to both FIGS. 1 and 2, reference characters 1Aa lAa 1Ba ,1Ba 1Ca Ca 1Da 1Da 1E a, 1Ea 1Fa and lFa indicate contacts of respective main floor contactors (not shown) for cars A, B, C, D, E and F, respectively, and each is closed when the associated car is at the main floor, opens when it is ordered to start and remains open while it is travelling at any other floor. Each of the abovedescrihed first-start contactors A, B, C, D, E and F actually includes make and break contacts arranged so that, when the contactor is thrown in, the make contact is first closed and then the break contact opens and that, when the contactor is opened, the break contact is first closed and subsequently the make contact is opened.

The operation of the present control system will next be described.

First assume that the traffic is normal and contact 1 in FIG. 1 is closed and that all the cars are standing at the main floor. Referring to FIG. 1, the closing of contact 1 completes a circuit including '692-1-6 to throw in the operational route contactor 2 common to the two groups. Assume further that first-start contactors A, B, C, D, E and F are all open and contacts 3A and 3D are closed. The throwing-in of the contactor 2 causes contacts 2a and 211 (FIG. 2) to complete a circuit including thereby to energize the first-start holding contactors 41 and 42 for the first and second groups, respectively. The closing of contacts 41a and 42a completes a circuit including in FIG. 1, thus to energize the first-start contactor A for car A. As the result, the make contact of the contactor A is first closed and then its break contacts Ab, and Ab are opened so that the contacts A holds itself by a circuit including G)1Aa --A-Aa 41a 9. At the same time, a circuit including is completed to energize the first-start contactor D for car D, which contactor thus holds itself by'a'circ'uit' in eluding 1Da D--Da 42a -6.

Upon energization of contactors A and D, elevators A and D operate to open their door inviting the waiting passengers on the main floor or hall. On this occasion, first-start contactors B and E for units B and E are not energized though the contacts 3A and 3D of the respective first-start preparing contactors are open and contacts 3B and 3E are closed. The reason for this is that position contacts Ab and Db are open and must be closed by cars A and D moving away from the main floor before contacts 3B and 3E will close. Referring to FIG. 2, the closing of contacts Aa or Da completes either a circuit including 6162b-Aa -6 to energize the group interlocking contactor 61 for the first group or a circuit including 696261b-Da 6 to energize the group interlocking contactor 62 for the second group.

Energization of either of the contactors 61 or 62 causes the contacts to open because of interlocking break contact 62b and 61b. The time limit relay ST is at the same time energized through closed contact 61a or 62a Thus, when the trafiic condition is normal, one of cars A, B and C in the first group and one of cars D, E and F in the second group are selected as first-starting cars to wait calls by the circuitry in FIGURE 1. However, if the group interlocking contactor 61 for the first group is energized car A is directed to start by a landing or a car call or after a predetermined time has expired, and the main floor contactor contact 1Aa (FIG. 1) is opened to deenergizc the first-start contactor A of car A. Upon deenergization of contactor A contact Ab is closed to complete a circuit including and thus the first-start contactor B for car B is energized and holds itself to designate car B as the next firststarting car in the first group. At this time, the group interlocking contactor 61 for the first group is opened by the opening of contact Aa (FIG. 2) and contact 61b is closed to form a circuit including G9-6261b-Da 6 to energize the group interlocking contactor 62 for the second group. Therefore, even if the contact Ba is closed immediately, the contactor 61 for the first group is not energized since the contact 6212 is open. These group interlocking contactors 61 and 62 serve their primary purposes only when the demand for service is light and have little to do with the elevator operation except directing alternative car dispatch of the group when the traflic is normal. Also at this time the time limit relay 5T opens because of the opening of contact 61a but its contacts STa and STa are not opened since the contact 62% is closed immediately. Now, the next first-starting car in the first group is car B and that in the second group is car D and the two groups operate in response to calls or upon the predetermined schedule independently from each other due to the fact that 2a1 is closed, and 2b1, 2122 are open in FIGURE 1. A further detailed explanation of this mode of operation is believed unnecessary and will not be given herein.

Now assume that the demand for service diminishes when car B has been selected as the first-starting car of the first group after the start of car A and that the interlocking contactor 62 is still energized. Under this situation, contact 1 (FIG. 1) is opened (by the command logic not shown) to deenergize the operational route contactor 2, thus its contacts 211;, and 2:1 in FIG- URE 2 are opened. Consequently, the first-start holding contactor 41 for the first group is opened (FIG. 2), but the first-start holding contactor 42 for the second group remains energized owing to the circuit including 4lb42aa5Taa Upon deenergization of contactor 41 the first-start contactor B for car B is opened due to opening of contacts 4111 in (FIG. 1) and the first group now includes no first- 3 start car to start next. In the second group the first-start contactor D for car D remains energized. In other words, when the traflic changes from a normal to a dull or slack condition, that elevator group including a car scheduled to start first of all the elevators installed in the building remains to be a first-starting car and the designation of the first-starting car in the other group is cancelled so that only the former group, which remains first-starting, continues to operate to meet the trafiic demand.

When the first-starting car, i.e., car D is given a starting order, contact 1Da in FIG. 1 is opened to open the first-start contactor D. Accordingly, position contact Db is closed to complete a circuit including so that the first-start contactor E for car E is energized and holds itself as the next first starting car. Suppose that cars A, B and C of the first group, for example, are all standing at the main floor available for service before or at the same time or after the contact E is energized. Assume further that the contact 3A is thrown in. Under these conditions, as can be seen in FIGURE 1, the contact A cannot be energized by circuit because Eb will be open when the contactor E is energized. Accordingly it will be appreciated that a group priority is given to either of the groups by contactors 41 and 42. Calls or service are thus answered or maintained only by the second group.

Next, suppose that both cars E and F are at any other floor or floors with the first-start contactor D for car D held in its energized state. Contacts 3E and 3F are not closed even when car D is ordered to start but contact 3A in the first group is closed as previously explained in connection with the first starting preparation contacts. Since car E stands at other floors, contact 1Ea is opened and thereby contactor E remains opened to keep closed contact E11 Consequently, a circuit including is formed to energize the first-start contactor A for car A to select it as the first-start car. On this occasion, however, even if contact 3A has been closed, if contact 3D or SP is closed and contacts 1Ea or 1Da is closed, then contact 3A reopened to select car D or E in the second group as the next first-starting car as long as car D or F in the second group returns to the first or main floor before car E is ordered to start.

It will be appreciated from the foregoing that the ele vator groups are interlocked so as to be operated collectively during the time when the traific is small and the first-start designation is shifted from the group including a car previously designated as a first-start car to the other group only when all cars in the former group other than the first-start car are at any other floor or floors. It will readily be understood that if the traffic restores its normal condition the groups again operate to respond to calls independently from each other. According to the present invention, it will be appreciated that an elevator control system is provided which is highly efficient in operation during the peaks of traffic and enables economic operation of the entire elevator plant even while the trafiic is small.

Having described one embodiment of a new and improved elevator control constructed in accordance with the invention, it is believed obvious that other modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiment of the invention described which is within the full intended scope of the invention as defined by the appended claims.

We claim:

1. An elevator control system for a plurality of elevators for dividing the elevators into a plurality of groups each having plural elevators, comprising; first-starting car selection means provided with each group and operable independently of the first-starting car selection means of other groups for selecting one of the elevators in the grOup as a first-starting car at the main floor; service demand detecting means for detecting whether the service demand for the elevators is normal or slack; control means operably coupled to and controlled by service demand detecting means and with said first-starting car selecting means of each group for operating said groups independently or as a unit depending upon whether the service demand is normal or slack, respectively, said control means including means for isolating each group so that it is operated independently of others when the service demand is normal and means for interconnecting all of the groups when the service demand is slack; priority selection means controlled by said control means for giving a priority in dispatch to one of the groups while the service demand is slack; said priority selection means further including interlocking means for maintaining groups other than the group given priority non-operative during the slack service condition and shifting means for making one of the other groups to select one of its available cars as a first-starting car; irrespective of said priority, if there is no available car at the main floor in the group which has been given the prority by said priority selection means; whereby each said group is operated independently of the other groups when the service demand is normal, but when the service demand is slack any one group that is given priority is operated according to said first-starting car selection means of the group with other groups being maintained non-operative and when all the elevators belonging to the group which has been given the priority are not available in case a call for service is registered, any one of the available cars of the other groups is made to provide the service.

2. An elevator control system according to claim 1, in which said control means further includes detecting means operably coupled with said shifting means for deecting if there is no available car at the main floor in the group which has been given the priority by said control means when a call for service is registered.

3. An elevator control system according to claim 1 wherein said control means further comprises means operably coupled with the first starting car selection means of each group for directing alternate dispatch of the cars from all the groups while the service demand is normal.

4. An elevator control system for controlling a plurality of elevators by dividing the elevators into a plurality of groups each consisting of a plurality of elevators, comprising first-starting car selection means provided with each group for selecting one of the elevators in the group as a first-starting car at the main floor; group priority selection means operably coupled with the first-starting car selection means of each group for selecting one of said groups as a first-starting group at the main floor; service demand detecting means operably coupled with said group priority selection means and said first-starting car selection means for detecting whether the service demand for the elevators is normal or small, control means responsive to said service demand detecting means for stopping the selecting function of said group priority selection means when the service is normal; said priority selection means further including interlocking means for preventing operation of groups other than the selected group and shifting means operably coupled with said interlocking means for releasing said interlocking means when there is no available car at the main floor in the group given priority.

5. An elevator control system according to claim 4, further comprising means operably coupled with said firststarting car selection means for directly alternate dispatch 7 8 of the cars from the groups while the service demand is 3,073,417 1/ 1963 Lusti 187-29 normal. 2,740,495 4/1956 Santini ct a1. 187-29 References Cited 2,973,059 2/ 1961 Hornung 187-29 2 960 187 ZTATES liATENTs 187 29 5 ORIS L. RADER, Primary Examiner.

runs et THOMAS LYNCH, Examiner.

3,022,865 2/1962 Hornung 187-29 

